[RESOLVED] How to validate data on datagridview to prevent duplicate

[khabib28]

for example i have "NID" as textbox and datagrid with @NID field.
i want save NID with Value "N001" to @NID on datagrid.
how to prevent duplicate when i save NID with value "N001" to datagrid.

I trying like this but error :

private sub save()  
dim dgv as datagridview1  
if dgv.CurrentRow.Cells(0).value = NID.text then  
msgbox("Data duplicate")  
else  
dgv.rows.insert(.NewRowIndex, NID.text)  
end if  
end sub

help me
thanks

[AceDuk]

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim Exists As Boolean = False
        For Each item As DataGridViewRow In DataGridView1.Rows
            If item.Cells(0).Value = NID.Text Then
                Exists = True
            End If
        Next
        If DataGridView1.Rows.Count > 0 AndAlso Exists = True Then
            MsgBox("Data duplicate")
            Exit Sub
        Else
            DataGridView1.Rows.Insert(DataGridView1.NewRowIndex, NID.Text)
        End If
    End Sub

[khabib28]

Problem solved ...
I used this code -->

 For i As Integer = 0 To dataspdibeli.Rows.Count - 1
            If Not IsDBNull(dataspdibeli.Rows(i).Cells("NID_SP").Value) AndAlso dataspdibeli.Rows(i).Cells("NID_SP").Value = spnid.Text Then

thanks <-_->
#junior_programmer